Why, shades of the 1960s! It’s been a while since a group of college students caused a campus event to be shut down.

I might be wrong, but I have a hunch it hasn’t been done since those student anti-war upheavals over 40 years ago.

This past Tuesday, New York City Police Commissioner Ray Kelly got a dose of what one of those 1960s protests must have felt like when he was shouted down at Brown University in Providence, R.I.

Kelly was supposed to deliver a lecture on “Proactive Policing in America’s Biggest City.” The disingenuousness of the subject matter might have been what raised the hackles of student activists.

I suspect it’s seldom that a crusty, curmudgeonly old conservative like myself finds himself in agreement with today’s college activists, since most of them would tend to espouse causes on the left side of the political spectrum.

But when it comes to Kelly — and his boss, New York City Mayor Michael Bloomberg — things no longer become an issue of Right vs. Left. They become an issue of whether we intend to ignore the U.S. Constitution or follow it.

Kelly and Bloomberg have what, in the kindest terms, might be described as an adversarial relationship with the Bill of Rights. They take to civil liberties the way Dracula takes to sunlight, only with less enthusiasm.

Both men supported the NYPD tactic of conducting surveillance on Muslim groups, even those outside the jurisdiction of New York City and state.

If those groups were engaging in constitutionally protected activity, then there’s an appropriate term for what Kelly and Bloomberg were doing.

It’s called “breaking the law.”

So when Brown officials invited the lawbreaker Kelly to give a speech in which he’d no doubt soft-soap that surveillance policy by calling it “proactive policing,” I’d expect some students to get a little ticked off.

But according to news reports, many of those who protested Kelly’s lecture — they got so loud, rambunctious and outrageous that it had to be shut down — had a problem with the NYPD’s stop-and-frisk policy.

Kelly and Bloomberg support that policy, too; they continue to support and defend it even after a federal judge ruled that many of the stop-and-frisks beat cops made were (a) illegal and (b) racially motivated.

According to Fox News, one of the protesters specifically shouted, “We want you to stop stopping and frisking people.”

Spoken like a bona fide, dyed-in-the-wool left-winger. Stop-and-frisks are perfectly legal — and appropriate — when an officer has reasonable suspicion to believe that the person he’s about to stop either has committed a crime or is about to commit a crime.

U.S. District Court Judge Shira Scheindlin heard witnesses who testified that far too many New York City cops were stopping and frisking people whose only crime was minding their own business.

One of those officers testified that his precinct commander specifically told him to stop black males between the ages of 14 and 21.

That sounds like the commander was not only encouraging illegal Terry stops, but also racial profiling as well.

Small wonder then that, according to Fox, another of the protesters was heard shouting, “Racism is not for debate!”

That student is probably not one of Brown University President Christina Paxson’s favorites.

“The conduct of disruptive members of the audience is indefensible,” Paxson said in a statement, “and an affront both to civil democratic society and to the university’s core values of dialogue and the free exchange of views.”

Perhaps she’s right, but I have a word of advice for Paxson: In the future, just don’t invite lawbreakers to give lectures on Brown University’s campus.

Gregory Kane, a Washington Examiner columnist, is a Pulitzer Prize-nominated news and opinion journalist who has covered people and politics from Baltimore to the Sudan.